GENETIC FINGERPRINTING FOR DETERMINING THE MODE OF REPRODUCTION IN PASPALUM-NOTATUM, A SUBTROPICAL APOMICTIC FORAGE GRASS

Paspalum is an important genus of the family Gramineae that includes s everal valuable forage grasses. Many of the species are polyploid and either obligate or facultative apomicts. Cyto-embryological observatio ns of several tetraploid genotypes of P. notatum were performed to det ermine their mode of reproduction. Afterwards, selfed progenies of the genotypes F131, Q3664 and Q4117 were analysed using RFLP and RAPD gen etic fingerprints to identify maternal and non-maternal (aberrant) pla nts, and to establish the degree of apomictic reproduction. Five maize clones and six primers were used for detecting genetic deviations fro m the maternal profile. Maize clones umc379, umc384 and umc318 and pri mers OPG10 and OPI4 were the most informative for discriminating betwe en maternal and aberrant individuals within the progenies of F131 and Q3664. The combined results of three RFLP clones or 4-6 RAPD primers w ere necessary to ascertain the mode of reproduction in plants F131 and Q3664. The results obtained with the RFLP and RAPD markers were in ag reement with the cyto-embryological studies in ascertaining the mode a nd degree of apomictic reproduction. Plant F131 showed a completely se xual reproductive behaviour, Q3664 an elevated expression of sexuality , while Q4117 was highly apomictic. A fingerprint analysis of an outcr ossing population, aimed at the identification of hybrid plants, was a lso performed. Maize clones um318 and umc379 and primers OPC2 and OPC9 were used, The presence of specific bands belonging to the male paren t permitted a rapid and easy detection of hybrids. The methodology des cribed here can be applied both for the characterisation of P. notatum populations and to identify hybrid progenies in Paspalum breeding pro grams.